What are the different types of prestressing strands?

Do you know what are the types of PC strands? As a PC strand manufacturer, we share this article with you.

Link to HUAYONGXIN

I. PC strand bonded

Bonded prestressing strand is a stranded steel cable composed of multiple high-strength steel wires that have been stress relieved (stabilized). It is suitable for prestressed concrete or similar applications. The main characteristics of bonded prestressing strands are high strength and good relaxation, in addition to being straighter when unfolded. The common tensile strength grade is MPa, and there are also strength grades such as , , , , MPa. The yield strength of this steel is also higher.

II.PC strand unbonded

Unbonded prestressing strand is made of ordinary prestressing strand coated with anticorrosive grease or paraffin wax and then wrapped with high-strength polyethylene. Bondless prestressing strands are mainly used in post-tensioning prestressing systems, the difference between them and bonded prestressing strands is that the prestressing does not bond with the surrounding concrete. During its working period, the prestressing tendon is always allowed to slide longitudinally relative to the surrounding concrete. The prestressing force is transmitted to the concrete exclusively by the anchorage. During construction, the unbonded tendons can be laid directly into the formwork like ordinary reinforcement. The concrete is then poured and the anchorage is tensioned after the concrete has reached its design strength, without the need for pre-drilled holes, grouting, etc.

III. Filled epoxy coated prestressing strand

Epoxy-coated filled strand has an average epoxy coating thickness of 0.6~0.8mm and is tested for continuity of coating before production. It is ensured that there are no more than 2 pinholes per 30m when the product leaves the factory. In addition to the excellent anti-corrosion properties, the epoxy resin coating has sufficient toughness. In the process of steel strand stretching, the epoxy resin coating extends synchronously with the steel wire without brittle cracking. When the strand is broken at the limit, the epoxy resin coating is consistent with the strand fracture. Compared with the PC strand, its ultimate strength is increased. The strand is completely wrapped with epoxy resin so that the strand forms a solid whole. Therefore, when the strand is tensioned with a clip anchor, the material properties of each wire are fully utilized. The overall strength of the strand can be increased by 2% to 3%.

It uses special surface treatment technology and a high-pressure electrostatic spraying method. It forms a uniform epoxy resin anti-corrosion layer with a certain thickness on the steel substrate. Make the physical and chemical properties of the product stable. It has the characteristics of heavy anti-corrosion, acid resistance, alkali resistance, salt resistance, temperature resistance, insulation, etc. The products are used in bridges, docks, airports, major buildings, sewage plants, especially on marine buildings. It can improve the service life by more than 50 years and is a new type of anti-corrosion steel for construction.

Huayongxin provides PC Strand Bonded and PC Strand Unbonded. If you are interested in our products, please feel free to contact us.

For more information, please visit PC Steel Bar.

Prestressed Material

The prestressing steel strand used in prestressing is typically made of high-strength, low-relaxation steel. It is commonly known as prestressing strand or prestressing wire. The prestressing steel strand is composed of multiple individual steel wires twisted together to form a helical shape. The wires are usually made of high-carbon steel with a diameter ranging from 5 to 15 millimeters.

The steel used for prestressing strand has high tensile strength, typically in the range of 1,860 to 2,200 megapascals (MPa). This high strength allows the strand to withstand the forces applied during prestressing without breaking.

To enhance the durability and performance of the strand, it is often coated with a protective layer of zinc or epoxy. This coating helps prevent corrosion and improves the bond between the strand and the surrounding concrete.

Prestressing strand for prestressed concrete is commonly used in various construction applications, such as precast concrete elements, bridges, high-rise buildings, and other structures that require enhanced load-bearing capacity and reduced deflection.

Are you looking for prestressed steel strand? We have been committed to steel strand manufacturing for many years. We provide various PC steel strands. Welcome to contact us.

Reinforcing Steel PC Strand for Concrete Prestressing Types

There are several types of prestressing steel strands used in construction, each designed to meet specific project requirements. Here are some common types:

1. Uncoated Prestressing Strand: This type of strand consists of multiple steel wires twisted together without any protective coating. Uncoated strands are primarily used in applications where corrosion protection is not a concern, such as temporary structures or indoor applications.

2. Galvanized Prestressing Strand: Galvanized steel strands have a zinc coating applied to the surface of the steel wires. The zinc coating provides corrosion resistance, protecting the strand from environmental elements. Galvanized steel strands are commonly used in situations where the structure may be exposed to moisture or corrosive conditions.

3. Epoxy-Coated Prestressing Strand: Epoxy-coated steel strands are coated with a layer of epoxy resin to provide corrosion protection. The epoxy coating creates a barrier between the steel and the surrounding environment, preventing the ingress of moisture and corrosive agents. This type of strand is widely used in structures where long-term durability is essential.

4. Stainless Steel Prestressing Strand: Stainless steel strands offer excellent corrosion resistance due to their high chromium content. They are particularly suitable for applications where the structure will be exposed to aggressive environments, such as marine environments or chemical plants.

5. Low Relaxation Prestressing Strand: Low relaxation strands are manufactured using a specialized process that minimizes the amount of relaxation or elongation that occurs over time. This type of strand is used when precise control of prestress losses is crucial. Low relaxation strands help maintain the desired level of prestress in the structure over an extended period.